Lens barrel

Abstract

In a lens barrel having a first holding tube holding a first optical system and a second holding tube holding a second optical system, support rollers are arranged at three parts on the periphery of each of the first and second holding tubes to restrain these optical systems from tilting. The positions of the support rollers are arranged to be respectively shifted from the centers of gravity of the holding tubes either forward or rearward in the direction of an optical axis. If the direction in which an image plane is caused to tilt by tilting of one of the two optical systems is opposite to the direction in which the image plane is caused to tilt by tilting of the other, the tilts of the image plane caused by the tilting movements of the two optical systems are arranged to offset and cancel each other by setting, for example, the support rollers of the first holding tube in rear of the center of gravity of the first holding tube and the support rollers of the second holding tube also in rear of the center of gravity of the second holding tube.

What is claimed is:  
     
       1. A lens barrel comprising: 
       a first holding tube holding a first lens group arranged to be driven in a direction perpendicular to an optical axis for correcting an image shake;  
       a second holding tube holding a second lens group arranged to be moved along the optical axis;  
       said first lens group and said second lens group being located on the same optical axis;  
       a first plurality of projections arranged at said first holding tube to protrude perpendicularly to the optical axis for restraining said first lens group from tilting with respect to the optical axis; and  
       a second plurality of projections arranged at said second holding tube to protrude perpendicularly to the optical axis for restraining said second lens group from tilting with respect to the optical axis,  
       wherein positions of said first plurality of projections and said second plurality of projections are respectively shifted with respect to positions of centers of gravity of said first holding tube and said second holding tube in the optical axis direction, and  
       wherein, if a direction of tilting of an image plane caused by tilting of said first lens group and a direction of tilting of the image plane caused by tilting of said second lens group are the same, a direction in which the position of said first plurality of projections is shifted with respect to the position of the center of gravity of said first holding tube and a direction in which the position of said second plurality of projections is shifted with respect to the position of the center of gravity of said second holding tube are opposite to each other, and  
       wherein, if a direction of tilting of an image plane caused by tilting of said first lens group and a direction of tilting of the image plane caused by tilting of said second lens group are opposite to each other, a direction in which the position of said first plurality of projections is shifted with respect to the position of the center of gravity of said first holding tube and a direction in which the position of said second plurality of projections is shifted with respect to the position of the center of gravity of said second holding tube are the same.  
     
     
       2. A lens barrel according to  claim 1 , wherein the positions of said first plurality of projections and said second plurality of projections are shifted in phase. 
     
     
       3. A lens barrel according to  claim 1 , wherein said second lens group is arranged to move along the optical axis for focusing. 
     
     
       4. A lens barrel according to  claim 1 , wherein said second lens group is arranged to move along the optical axis for zooming. 
     
     
       5. A lens barrel according to  claim 1 , wherein: 
       the second lens group tilts in the direction for correcting the movement of the image due to the tilting of the first lens group.  
     
     
       6. A lens barrel comprising: 
       a first holding tube holding a first lens group arranged to be driven in a direction perpendicular to an optical axis for correcting an image shake;  
       a second holding tube holding a second lens group arranged to be moved a long the optical axis;  
       said first lens group and said second lens group being located on the same optical axis;  
       a first plurality of projections arranged at said first holding tube to protrude perpendicularly to the optical axis for restraining said first lens group from tilting with respect to the optical axis; and  
       a second plurality of projections arranged at said second holding tube to protrude perpendicularly to the optical axis for restraining said second lens group from tilting with respect to the optical axis;  
       wherein positions of said first plurality of projections and said second plurality of projections are respectively shifted with respect to positions of centers of gravity of said first holding tube and said second holding tube in the optical axis direction;  
       wherein, if a direction of tilting of an image plane caused by tilting of said first lens group and a direction of tilting of the image plane caused by tilting of said second lens group are opposite to each other, a direction in which the position of said first plurality of projections is shifted with respect to the position of the center of gravity of said first holding tube and a direction in which the position of said second plurality of projections is shifted with respect to the position of the center of gravity of said second holding tube are the same.  
     
     
       7. A lens barrel comprising: 
       a first holding tube holding a first lens group arranged to be driven in a direction perpendicular to an optical axis for correcting an image shake;  
       a second holding tube holding a second lens group arranged to be moved along the optical axis;  
       said first lens group and said second lens group being located on the same optical axis;  
       a first plurality of projections arranged at said first holding tube to protrude perpendicularly to the optical axis for restraining said first lens group from tilting with respect to the optical axis; and  
       a second plurality of projections arranged at said second holding tube to protrude perpendicularly to the optical axis for restraining said second lens group from tilting with respect to the optical axis;  
       wherein positions of said first plurality of projections and said second plurality of projections are respectively shifted with respect to positions of centers of gravity of said first holding tube and said second holding tube in the optical axis direction;  
       wherein said second lens group tilts in the direction for correcting the movement of the image due to the tilting of said first lens group.